Improvement in screw



dinard ,statrt anni @Mira A. W. OWEN AND'JAMES BARNES, OF EAST. CANTON, PENNSYL- VANIA.

Leners Parma No. 93,552, 1aed August 10,1869.

IMPROVEMENT IN scnr'zwfpmrrzzs.

The Schedule referrea to in these Letten Patent and making part of the same.

To all whom it lmay concern:

.1ication, and in which-TA Figure l represents a side view, and

Figure-2, an end view of our screw-plate.

Similar letters of reference indicate like parts in both figures.

The nature of o ur invention consists in the employment of a bar, formed with bifurcated arms, which are formed, at their npper ends, with screw-thread plates, the said bar being provided with a clamp, and operated by means of a' set-screw, substantially Vin the ninnner, and for the purpose described.

To enable others skilledin the art to which our invention appertajns, to make and use the same, we will now describe its construction and operation.

In the accompanying drawings-v ,A represents a bar, which is cast solid with -the forked arms b b, each arm being provided, at its upper end, with the projections a a, which are cast solid with the arms b b,.and formed, on'their inner surface, with the screw-threads, as seen in fig. 1.

d 'represents the clamp, tting over the upper ends. of the arms b b, the said clamp being provided with the set-screw c, by which one ofthe forks is placed at any desired dista-nce from the other.

The end of the bar A is intended to be placed into a common anvil.

Having thus fully described onrimfention, What we claim as new, and desire to secure by Letters Patent, is-v Constructing screw-cutting dies a a, on the enlarged extremities of the spring-forks b @projecting from, but in one piece withthe stock A, and combining therewith the clamp d and set-screw c, substantially as described.

In vtestimonythat we claim-the foregoing as our own, we aiiix om: signatures, in presence of two'wit- 

